The set for Dr. Rukh's laboratory appeared as that of Ming the Merciless in Flash Gordon (1936) and Countess Zelaska's castle in Dracula's Daughter (1936).
The church in which Frank Lawton and Frances Drake get married, though called the "Church of the Six Saints" in the film, is actually the set of Notre-Dame Cathedral recycled from the Universal production The Hunchback of Notre Dame (1923). starring Lon Chaney (Sr.)
Early in the film, Janos Rukh projects a view of the Earth as seen from outer space. The sound effect of the meteor approaching the Earth was used continually by Universal Pictures as that of the rocket ships in its Flash Gordon and Buck Rogers movie serials.
In 1986 actress Frances Drake recalled that the crew played a joke on star Boris Karloff. They raised him up on a platform that was intended to lower him down into the radium pit. They raised him up high over the pit and left him there when they broke for lunch. According to Drake, the actor was a good sport about it.
The scene of Boris Karloff being lowered into the pit containing the Radium X meteor was reused in a Universal serial, The Phantom Creeps (1939), starring Bela Lugosi. Karloff essentially "doubled" for Lugosi in the sequence since in "The Phantom Creeps" it was Lugosi who was lowered into the pit.